Mechanical analysis and resilience-driven design of underground vertical shaft ring beam considering circular arch effect

Abstract
This study investigates the influence of the ring beam’s circular arch effect on the mechanical performance and resilience of support systems in ultra-deep circular shafts. The planar elastic foundation beam method is combined with three-dimensional elasto-plastic finite element analysis, using the Beijing Urban Sub-center Station transportation hub project as a case study. The results demonstrate that the circular arch effect significantly enhances the structural load-bearing capacity, stability, and resilience. Numerical simulations reveal that although the original design of the diaphragm wall meets regulatory requirements, it remains conservative and offers optimization potential. Consequently, key parameters, including the wall thickness, number of ring beams, and their spacing, were optimized to improve structural resilience. The proposed design schemes ensure structural safety, offering substantial economic benefits and practical application value. This research provides an important reference for the resilience-driven design of circular foundation pit support structures.